The present invention relates generally to relationships for controlling active suspension apparatus for vehicles, in particular rail vehicles, and more particularly to a method and apparatus for controlling actuator apparatus for active suspension of vehicles, in particular rail vehicles.
The following description relates to actuator apparatuses implemented in prior art active suspensions for rail vehicles.
Such actuator apparatuses, e.g. hydraulic, pneumatic, or electric actuators, are associated with transverse or vertical secondary suspension systems on rail vehicles to obtain a more comfortable ride.
A first prior art solution, implemented by Fiat in tilting trains ETR450, ETR460, and ETR470 now in commercial service, is characterized by the use of pneumatic actuators acting in parallel with the secondary suspension to as to perform body-bogie re-centering on curves taken at very high speed.
This re-centering is necessary because of the architecture of the Fiat tilting bogie in which the tiltable bolster (i.e. cross-member) is situated above the secondary suspension.
Another prior art solution is implemented by SGP from the Siemens Group, and was presented at the 28th xe2x80x9cModerne Schienenfahrzeugexe2x80x9d rail conference in Graz, Austria, in October 1993.
That solution includes apparatus having actuators which may be pneumatic and which are disposed in parallel with the secondary suspension.
In such a solution, the control signal for controlling the actuator is essentially a function of the transverse offset between the body and the bogie as measured by a sensor.
Another prior art solution is implemented by Hitachi in the Shihkansen 400 and is described in the article published in the October 1992 edition of xe2x80x9cJapanese Railway Engineeringxe2x80x9d.
In addition, Hitachi""s Document JP 8 048 243 which is applicable to the WIN350 prototype train describes implementing pneumatic or hydraulic actuators in parallel with the secondary suspension.
That prior art solution uses inertial sensors of the accelerometer type in the vehicle body.
The object of that document is to reduce vibration level to within a narrow frequency band.
Such vibration characterizes sustained yaw motion of the carriages.
Another prior art solution is implemented by Faiveley.
Documents FR 2 689 475 and FR 2 689 476 relate to that solution.
A prototype vehicle based on a main-line passenger car or xe2x80x9ccarriagexe2x80x9d uses pneumatic cushions disposed horizontally between the body and the bogies and acting transversely.
The cushions are controlled so as to regulate the transverse position of the body relative to the bogie about a zero position.
Such regulation is however akin to servo-controlling position.
In such a solution, the control signals are generated on the basis of a single sensor for sensing transverse displacement between the body and the bogie.
From the actuator apparatus implemented in prior art active suspension apparatus on rail vehicles, it can be seen that it is known that actuator apparatuses can be disposed in parallel with the secondary suspensions of rail vehicles.
In addition, two modes of control are envisaged: a first mode consists in using the actuator under conditions in which position is servo-controlled, and a second mode consists in using the actuator under conditions in which force is servo-controlled.
From actuator apparatus implemented in prior art active suspension apparatus on rail vehicles, it can be seen that the most commonly used sensors are of the inertia type (accelerometers) and of the inductive type (measuring relative displacement and relative velocity, between two moving bodies).
An object of the invention is thus to improve the smoothness of the ride experienced by the passengers in articulated trains of vehicles, in particular of the very high speed train type, so as to enable such trains to operate at speeds higher than 350 km per hour while retaining the level of comfort currently observed on trains running at 300 km per hour.
This improvement must be obtained without providing additional apparatus relating to the track, e.g. apparatus for pre-recording track curves, smart beacons, etc.
The merit of the Applicant is to teach the use of a particular articulated train architecture to derive information that cannot be obtained by using known sensors and that can be used to control actuator apparatus.
In other words, the present invention consists in taking advantage of the articulated train architecture currently implemented in the Applicant""s very high speed trains and in enabling the articulated train to be used as a track inspection vehicle to derive the local curvature of the track in real time.
According to the invention, the control apparatus for controlling actuator apparatus implemented in active suspension apparatus for vehicles, in particular rail vehicles, is characterized in that it uses the articulated architecture of the train to derive the local curvature of the track in real time.
The control apparatus of the invention for controlling actuator apparatus implemented in active suspension for vehicles also satisfies at least one of the following characteristics:
the control signal transmitted by said control apparatus to the actuator apparatus of the bogie of order n in the articulated train is a function of measurements of at least one deflection angle xcex1i at an articulation center situated between adjacent carriages and of the position offset hj of said articulation center relative to the track;
said actuator apparatus is force servo-controlled, said actuator apparatus setting the force applied to a vehicle body of an articulated train of vehicles from a bogie n associated with said body, said control apparatus delivering a general control signal, signaln, for bogie n, that is a function of an intermediate parameter xcex4n that is a function of at least one deflection angle xcex1i and of at least one position offset hj of said articulation centers relative to the track;
said intermediate parameter xcex4n for n greater than 2 is given by the following formula:
xcex4n=xcex1n/2+xcex1n+1+(3xc2x7hn+1xe2x88x922xc2x7hn+2xe2x88x92hnxe2x88x921)/(2xc2x7d)
xe2x80x83where:
d is the distance between two articulation centers in the length direction;
xcex1n is the deflection angle of the articulation center at the bogie n; and
hn is the position offset of the articulation center of the bogie n relative to the track;
for the second (n=2) bogie of the train, xcex42 is given by the following formula:
xcex42=xcex12/2+(2xc2x7h2xe2x88x92h3xe2x88x92h1)/(2xc2x7d)
and for the first (n=1) bogie of the train, xcex41=0; and
said general control signal signaln for bogie n is given by the following formula:                               signal          n                =                  xe2x80x83                ⁢                              Gain1            ·                          (                                                V                  TMn                                -                                  V                  TVn                                            )                                +                      (                                          V                x                            ·                              δ                n                                      )                                                  =                  xe2x80x83                ⁢                  Gain1          ·                      (                                                            ⅆ                                      /                                          ⅆ                      t                                                                      ⁢                                  xe2x80x83                                ⁢                                  (                                      h                    n                                    )                                            +                                                V                  x                                ·                                  δ                  n                                                      )                              
xe2x80x83where:
VTMn represents the transverse velocity of a point M belonging to the vehicle body and located at the articulation center;
VTvn represents the transverse velocity of the point belonging to the track that, in the horizontal plane and when the train is stationary, coincides with the point M; and
Vx represents the velocity at which the train is advancing.
According to the invention, the method of controlling actuator apparatus implemented in active suspension apparatus for vehicles, in particular rail vehicles, is characterized in that it includes a step consisting in using the articulated architecture of the train to derive the local curvature of the track in real time.
The method of the invention for controlling actuator apparatus implemented in active suspension for vehicles also satisfies at least one of the following characteristics:
said control signal transmitted by said control apparatus to the actuator apparatus of the bogie of order n in the articulated train is a function of measurements of at least one deflection angle xcex1i at an articulation center situated between adjacent carriages and of the position offset hj of said articulation center relative to the track;
said actuator apparatus is force servo-controlled, said actuator apparatus setting the force applied to a vehicle body of an articulated train of vehicles from a bogie n associated with said body, said method including a step consisting in delivering a general control signal, signaln, for bogie n, that is a function of an intermediate parameter xcex4n that is a function of at least one deflection angle xcex1i and of at least one position offset hj of said articulation centers relative to the track;
said intermediate parameter xcex4n for n greater than 2 is given by the following formula:
xcex4n=xcex1n/2+xcex1n+1+(3xc2x7hn+1xe2x88x922xc2x7hn+2xe2x88x92hnxe2x88x921)/(2xc2x7d)
xe2x80x83where:
d is the distance between two articulation centers in the length direction;
xcex1n is the deflection angle of the articulation center at the bogie n; and
hn is the position offset of the articulation center of the bogie n relative to the track;
for the second (n=2) bogie of the train, xcex42 is given by the following formula:
xcex42=xcex12/2+(2xc2x7h2xe2x88x92h3xe2x88x92h1)/(2xc2x7d)
and for the first (n=1) bogie of the train, xcex41=0; and
said general control signal signaln for bogie n is given by the following formula:                               signal          n                =                  xe2x80x83                ⁢                              Gain1            ·                          (                                                V                  TMn                                -                                  V                  TVn                                            )                                +                      (                                          V                x                            ·                              δ                n                                      )                                                  =                  xe2x80x83                ⁢                  Gain1          ·                      (                                                            ⅆ                                      /                                          ⅆ                      t                                                                      ⁢                                  xe2x80x83                                ⁢                                  (                                      h                    n                                    )                                            +                                                V                  x                                ·                                  δ                  n                                                      )                              
xe2x80x83where:
VTMn represents the transverse velocity of a point M belonging to the vehicle body and located at the articulation center;
VTvn represents the transverse velocity of the point belonging to the track that, in the horizontal plane and when the train is stationary, coincides with the point M; and
Vx represents the velocity at which the train is advancing.
One advantage of the method and apparatus of the invention for controlling a force servo-controlled actuator is that performance is increased without requiring any increase in the numbers of sensors, of processing apparatuses, or of actuator apparatuses.